1. Technical Field
The invention relates to nanotechnology and the fabrication of nano-scale structures. In particular, the invention relates to fabrication of a nanowire and a device having a nanowire using wet chemical etching.
2. Description of Related Art
A consistent trend in semiconductor technology since its inception is toward smaller and smaller device dimensions and higher and higher device densities. As a result, an area of semiconductor technology that recently has seen explosive growth and generated considerable interest is nanotechnology. Nanotechnology is concerned with the fabrication and application of so-called nano-scale structures, structures having dimensions that are often 50 to 100 times smaller than conventional semiconductor structures. Typically, either e-beam patterning or nano-imprinting combined with dry etching, such as reactive ion etching (RIE), are techniques used to fabricate nano-scale structures.
However, e-beam lithography is slow and therefore of limited use in high throughput or production situations. Moreover, e-beam lithography has limited resolution in the nano-scale range. While nano-imprinting is viable, the RIE process used therewith causes crystal degradation, introduces surface roughness in the sidewalls of the patterns, and uses a metal mask that contaminates the nano-structures with metal ions. Moreover, the conventional RIE process tends to impose limitations on the dimensions of the fabricated nano-structures. For example, the mask used in RIE etching mimics or even exacerbates the sidewall roughness of the nano-patterns because the mask remains rough at the micro-scale even with extreme precision writing.
Whether used with e-beam patterning or nano-imprinting, the surface roughness imparted on sidewalls of fabricated nano-structures by the RIE process is unacceptable at such nano-scale dimensions. For example, such surface roughness impacts nano-structure performance and reliability and limits nano-structure design, such as spacing or pitch between nanowires, for example. Moreover, the fabrication of nano-structures using e-beam patterning or nano-imprinting with RIE is time consuming. As such, production quantities of nano-structures fabricated conventionally can be costly.
Accordingly, it would be desirable to fabricate nano-structures with higher reliability and performance and higher nano-scale resolution with less surface roughness (i.e., smoother surfaces) at potentially lower cost and higher throughput. Such a fabricated nano-structure would solve a long-standing need in the area of nanotechnology.